Abstract
We present results from N -body simulations of the clustering properties of the universe in a cubic box of size 260 h −1 Mpc, within a cold dark matter (CDM) cosmology with skewed distributions for initial adiabatic density perturbations δ M . We consider two non-Gaussian models, Chi-squared and Lognormal , where the primordial gravitational potential is obtained from a non-linear transformation on a Gaussian random field. Our procedure yields for each model two primordial density distributions with opposite skewness δ 3 M . The gravitational evolution and the present statistical properties of our simulations are strongly sensitive to the sign of the initial skewness. Skew-positive simulations produce a highly lumpy distribution with little power on large scales. Skew-negative simulations, on the contrary, evolve towards a cellular structure with high power on large scales, showing, in many respects, better agreement with observations than the standard CDM model. Giving up the random-phase hypothesis for primordial perturbations seems then a viable possibility to reproduce the large-scale properties of the universe; such a possibility is further motivated by many physical models either within the inflationary dynamics or phase transitions in the early universe.
Published Version
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